Recently, semiconductor wafers (hereinafter, referred to as “wafers”) having large diameters are currently being developed, for example, in a process of manufacturing a semiconductor device. Also, thinner wafers are in demand for process such as mounting or the like. For example, if a thin wafer with a large diameter is transferred or polished as it is, there is a possibility that the wafer is warped or cracked. Therefore, in order to reinforce the wafer, the wafer is joined to, for example, a wafer or a glass substrate, which is a support substrate.
Joining of such wafer and the support substrate is performed by interposing an adhesive between the wafer and the support substrate, for example, using a joining apparatus. The joining apparatus has, for example, a first holding member configured to hold the wafer, a second holding member configured to hold the support substrate, a heating mechanism configured to heat the adhesive arranged between the wafer and the support substrate, and a moving mechanism configured to move at least the first holding member or the second holding member in a vertical direction. Also, in the joining apparatus, after supplying the adhesive between the wafer and the support substrate and heating the adhesive, the wafer and the support substrate are pressed and thus joined together.